GULF WAR SYNDROME?
Shortly after returning to the United States following the conclusion of Operation Desert Storm, a number of veterans of the Gulf War began reporting unexplained illnesses. Symptoms were varied, with the most commonly reported being joint pain, rashes, shortness of breath & chest pain, insomnia, poor cognition, chronic fatigue, and intermittent diarrhea.
Reports in the popular press suggested the possible existence of a "Gulf War Syndrome (GWS)." Sensationalized accounts and growing hysteria in some quarters included associating birth defects with service in the Kuwait Theater of Operations (KTO). Possible causes cited in the media included infectious disease, the release of biological warfare agents, exposure to environmental toxins (i.e. burning oil well fires), experimental drugs and vaccines, chemical warfare agents and radiation exposure from depleted uranium ordnance. These reports generally ignored the absence of similar symptoms in allied forces or the civilian populations of Kuwait and eastern Saudi Arabia.
It was obvious from the earliest stages that there was not a biological entity involved in all of the cases causing the disease. The disease, if it actually existed, was most likely caused by an exposure unique to the Desert Storm milieu.
There were a variety of exposures created by situations in the KTO that are known to be capable of causing illness.
A. Chemical exposures
Oil Well Fires: KTO veterans were exposed to high concentrations of petrochemical emissions resulting from the ignition of several hundred oil wells by Iraqi forces. These exposures were limited to troops actually in the area of the fires.
Chemical Agent Resistant Coatings. The evidence suggests that a small number of troops, specifically a guard unit from Florida, were exposed to this paint used on vehicles deployed to the region. Hence only a small number of individuals should be experiencing disease from this agent.
Chemical warfare agents. Exposure to chemical warfare agents remains controversial. Chemical weapons and mustard gas mines were reportedly identified. Chemical warfare agents as causes of a GWS type disease seem unlikely however. The symptoms it causes are acute and unmistakable -- not diffuse, chronic maladies.
B. Biological exposures
In addition to the usual infectious diseases associated with armies everywhere, troops sent to Saudi Arabia were exposed to other biological exposures not normally encountered.
Vaccines: Troops were inoculated against expected infectious diseases as well as two agents of biological warfare -- anthrax and botulinum toxin. All the vaccines, except for the latter two, are standard immunizations administered to all enlisted personnel and are also routinely given to civilians. Both the anthrax and botulinum vaccines have been available for many years and have been given to thousands of civilians and military personnel. No long term adverse effects have been documented.
Leishmaniasis. Leishmania tropica is a parasite typically causing skin lesions. One of the surprises of the Gulf War studies is that the organism was also capable of causing visceral disease. The exact number of troops exposed is unknown. Attempts to identify the organism in KTO veterans has identified less than 200 cases, but this may be due more to the absence of adequate lab tests than a low number of cases. The disease is known to cause persistent low grade fever and fatigue.
Pyridostigmine bromide. This drug, which binds with acetycholinesterase, was given to troops as a nerve agent pre-treatment. Short term adverse effects were noted in some personnel (5-50%) including nausea, genitourinary effects, headaches, rhinorrhea (runny nose), dizziness, abdominal cramping and tingling of the extremities. Less than 1% resulted in a medical visit. US troops seem to have been unique in that they were the only deployed forces using this drug and it would seem a likely candidate. However the drug has been used in clinical medicine for decades in patients with myasthenia gravis in doses up to seven times higher that given to US forces without any significant long term effects noted nor with chronic symptoms.
C. Deployment/Combat-related Stress
These include sudden mobilization in a hot, sandy, strange southwestern Asian desert; exposure to the largest oil wells in history which spilled smoke and oil over a vast area and the possibility of chemical and biological warfare. Although warfare has always been stressful and fear-inducing, Desert Storm was the first conflict in which the real threat of chemical warfare was known to the troops in advance of hostilities and the first in which the use of biological agents was expected.
Because of their poor handling of Agent Orange exposure related disease in the aftermath of Vietnam, both the Department of Defense and Department of Veteran Affairs were accused of engaging in a cover-up of the extent and magnitude of the "Gulf War Syndrome" by several groups. Consequently the Centers for Disease Control and Prevention (CDC) was requested to conduct an epidemiologic investigation into the issue of "Gulf War Syndrome."
Illness is inevitable in any group of 700,000 persons. The first question to be asked was: Were Desert Storm veterans suffering more than their share? Numbers varied based on reporting sources but approximately 7-13,000 (1-1.8%) individuals reported chronic illnesses and were placed on the Department of Defense or Veteran Affairs registries at their request.
A number of epidemiologic studies were conducted to determine if there was a larger degree of unexplained illness among KTO veterans than the military population in general.
In epidemiologic methodology suspected associations between exposure and disease are subjected to a series of analyses, statistical in nature, which attempt to prove the association between a disease and an exposure. Typically two populations with similar characteristics, except for the exposure, are compared. If the rate of disease is higher in the exposed than the unexposed an association is said to exist. Whether the association is causal depends on a) temporal association; b) reproducibility (i.e. the same results are obtained from different groups); and c) biological feasibility (i.e. the exposure is known or believed to be able to affect the organ systems involved).
A CDC study using members of a Pennsylvania Air National Guard Unit indicated that there was a statistical association with deployment to the Gulf and symptoms persisting more than six months consisting of one or more of the following: intermittent diarrhea, poor cognition, chronic fatigue and gastrointestinal symptoms. There was no statistical difference between deployed and non-deployed personnel for rashes, joint pain, depression, chronic migraines, unrefreshing sleep, or respiratory disorders. Physical examinations and laboratory tests revealed there were no consistent abnormalities. Earlier studies had produced similar results.
At the same time these abnormalities were not consistent from person to person or within groups. These findings created an immediate problem since the presence of consistent symptoms among persons with the disease is required to define a disease or syndrome. There is currently no evidence to support the existence of a consistent set of symptoms among individuals claiming to suffer from Gulf War Syndrome. In essence there is no disease or group of symptoms that can be characterized as a Gulf War Syndrome. This does not mean that service in the KTO did not lead to disease, only that there is no one disease and hence, no one cause.
There is no question that a number of Desert Storm veterans became very ill after their return to the United States. However, the symptoms reported by the veterans are multisystemic, usually unassociated with objective signs of pathology, and not easily distinguished from other multisystem complexes that have been described such as post-traumatic stress disorder, chronic fatigue, fibromyalgia and somnatiform disorders. There is, in other words, no biological or statistical basis for a Gulf War Syndrome.
There is no proof for a Gulf War Syndrome. Symptoms reported by veterans are too diffuse, inconsistent and varied to support a single cause. A variety of known illnesses are the most likely cause for the symptoms suffered by KTO veterans, chief of which are chronic visceral leishmaniasis and post-traumatic stress disorder (PTSD). Neither of these are known to cause long term health effects if identified and treated promptly.
A number of veterans organizations reject a major role for PTSD in the symptoms experienced by those returning from the Gulf. This is understandable -- no one likes to be told that their illness is "all in their head." But PTSD does adequately explain a) the multiplicity of unrelated symptoms; b) the chronicity of the symptoms despite the lack of etiologic agents; and c) the absence of the illness in the civilian populations of Saudi Arabia and Kuwait (their stress, while real, was clearly at a different and lower level).
On the other hand, neither PTSD nor leishmansiasis can explain a number of symptoms, particularly acute sensitivity to ordinary chemicals. There is some evidence that "multiple chemical sensitivity" may be accounting for most of these cases in some groups. MCS is caused by intense exposure to a chemical, certainly something troops in Kuwait during the height of the oil well fires encountered.
--T W Gideon
The author has been a practicing medical epidemiologist in Saudi Arabia for the past ten years and was in the Eastern Province during the Gulf War.
Institute of Medicine. Health consequences of service during the Persian Gulf War: initial findings and recommendations for immediate action. Washington, DC: National Academy Press, 1995
Unexplained illness among Persian Gulf War veterans in an Air National Guard Unit: Preliminary Report -- August 1990-March 1995. MMWR 44:443-45 (June 16,1995).
National Institutes of Health Technology Assessment Workshop Panel. The Persian Gulf Experience & Health. Journal of American Medical Association 272:391-3 (1994)